In copending application Ser. No. 135,131, filed Apr. 19, 1971, now U.S. Pat. No. 3,771,857, there is disclosed a cross-stripe filter in which the stripes cross over each other. In certain applications, there is a need for a filter which has parallel stripes which cannot be fulfilled with the cross-striped filter. With prior art processes it has been dificult, if not impossible, to obtain perfectly butted stripes. There is, therefore, a need for such a filter and a method for making the same.